A storm surge has caused the worst flooding on Germany's north-east coast since 2006, leaving streets and cars submerged and causing major damage.
Towns and cities along the Baltic coast were flooded, from Kiel in the far north to the resort island of Usedom near the Polish border.
Sea levels were recorded in the port of Wismar at 1.83m (6ft) above normal overnight.
Severe winter conditions also hit Sweden and Finland.
The overnight temperature fell to -41.7C at Muonio in Finnish Lapland, near the north-western border with Sweden, the coldest night of the winter so far.
Further west in northern Sweden, temperatures fell as low as -41.3C and road conditions were treacherous in much of the country.
A passenger train became stuck without power and heating for several hours in the north-eastern Norrbotten region with outdoor temperatures at -38C. Swedish media said no replacement buses were prepared to venture out because of the cold.
Some of the worst flooding in northern German was in the historic centre of Rostock and in Stralsund, as well as on Usedom, where major damage was reported. Outdoor staircases were washed away and snack bars badly affected.
"This is no children's tea party," said one local official. However, water levels were expected to fall in the coming hours.
Storm Axel was also responsible for the arrival of several hundred thousand plastic eggs on the island of Langeoog on Thursday.
Local reports said the eggs contained little toys with Russian messages inside and appeared to have come from a container that had fallen off a ship.